I've still be unable to raise the $250,000 I need to field an X-Prize entry
for a 100 MPG automobile.

Maybe if I give details of my plans then the funds will come in...

Well, consider the Audi A2 with the 1.2 diesel engine. The car has four
seats, weighs 1881 pounds, has 60 horsepower, has 103 foot-pounds of torque,
and gets 87 MPG in highway driving. Also the car is probably a little short
of the performance requirements.

Obviously the car could make 100 MPG if it were lightened. But the car
already has an aluminum frame and bodywork. Sure someone could make a carbon
fiber frame and bodywork for it but that is very expensive. And another
problem is that the 1.2 diesel engine likely only meets older Euro emission
standards.

In fact the only diesel car engines available in the U.S. in 2009 will
likely be 2.0 or larger.

And while there are some motorcycle engines with water-cooling, four-valve
heads, and fuel injection...the motorcycle engines do not meet automobile
emission requirements.

So my three entries are based on the above fundamentals.

The first entry will be a Lotus Elise with a 1.5 Yaris engine. The Lotus
Elise weighs 1984 pounds while the Yaris weighs 2295 pounds. Since the Yaris
gets 36 mpg and since the Elise weighs 14% less than the Yaris I'll estimate
the Entry1 mpg at 41 mpg. Then I'll further estimate the Entry1 mpg at 50
mpg based on gearing to required performance level. Also I could have a
thinner fiberglass bodywork made for Entry1 and thus will stick with the 50
mpg prediction.

But that's only halfway to the 100 mpg requirement ? Yeah, and consider that
all current cars have an engine control module that can't be directed by the
tuner. However, the ECM sends an electronic signal to the fuel injection and
therefor an electrical engineer could develop a system that interrupts the
signal to the fuel injection every other time on each cyclinder. Then
theoretically the engine uses half the fuel. Then the interrupt sytem could
activate only above 1500 rpm so that the engine is smooth at idle.

Would a fuel injection interrupt system work...meaning would the
four-cyclinder engine be smooth enough ? And would the fuel injection
interrupt system double the fuel mileage ? And finally would the fuel
injection interrupt system meet the performance levels ? Well, without
testing I don't know...

But the hope is that Entry1 has reached 100 mpg...

And that seems like a lot of hope so that leads to Entry2.

Entry2 is the KTM X-BOW with its 2.0 tubocharged VW engine replaced with a
2009 U.S.A. 2.0 VW diesel. Now the X-BOW has a carbon fiber frame and weighs
1650 pounds but the X-BOW will need bodywork added since climate control is
required. So put the weight at 1850 pounds.

Now the 2.0 VW diesel engine will probably get 45 mpg in a 3200 pound car.
Figure on 42% less weight and Entry2 gets 64 mpg. And 64 mpg could also
depend on gearing to the performance level. Now try the fuel injection
interrupt system on Entry2 and hope for 128 mpg...or be very satisfied with
100 mpg.

Oh, Entry3 is the Caterham 7 wide-frame special- ordered in aluminum and the
use a 2009 U.S.A. 4-cyclinder diesel engine along with a rear-wheel-drive
transmission. And subframes along with custom bodywork will enclose the
wheels and make a swing-back top. Of course the fuel injection fuel
interrupt system is also needed...

You are missing something here.
Weight is not the biggest problem when designing for high MPG.
If weight were dominant, a motorcycle @ 400# + 150# rider = 550#,
according to you that should get several hundred MPG.
Well it ain't so.

Now in a car I increase MPG by reducing weight but then I also want to scale
the engine size to the new weight. Since I don't have the engine size that
I need then I look at means of making a large engine act like a smaller
engine.

Aerodynamics is a relevant fundamental. But both drag coefficient and
frontal area together make the total amount of drag.

So an aerodynamic car is low to the ground.

In fact front spoilers and side skirts reduce drag by reducing the amount of air flow under the
car. The front spoiler can look bad but work very well. Now the front
spoiler also reduces lift by such a large amount that there will never be a
rear spoiler that reduces lift at the rear by the same amount. That leads to
rear wings but a rear wing might add drag while a rear spoiler will reduce drag.

In fact front spoilers and side skirts reduce drag by reducing the amount
of air flow under the
car. The front spoiler can look bad but work very well. Now the front
spoiler also reduces lift by such a large amount that there will never be
a
rear spoiler that reduces lift at the rear by the same amount. That leads
to
rear wings but a rear wing might add drag while a rear spoiler will
reduce drag.

This is so wrong in so many places, it's hard to start.
Front/side spoilers on race cars are meant to create a vacuum under
the car, increasing downforce, (weight to you).
Rear wings do the same.

Race cars are worse than a brick when speaking of aerodynamics. They
are designed to use airflow to INCREASE the apparent weight of the
vehicle.